1. Field of the Invention
The present invention generally relates to a method of cleaning a reaction chamber, particularly cleaning silicon- or metal-oxide, nitride, or oxynitride deposits from the reaction chamber.
2. Description of the Related Art
In a single-substrate processing apparatus, while depositing a silicon- or metal-oxide or nitride film on a substrate, a film is not only formed on the substrate but also on inner surfaces of a reaction chamber. Unwanted film on the inner surfaces produces particles which deposit on the substrate during film deposition processing which as a result deteriorate the quality of the film on the substrate. Thus, the reaction chamber is cleaned periodically by using an in-situ cleaning process. Accumulation of adhesive products on surfaces of electrodes may affect plasma generation or distribution over a substrate and may cause damage to the electrodes. The materials deposited in these areas can affect the deposition rate from substrate to substrate and the uniformity of the deposition on the substrate.
Several methods for cleaning reaction chambers have been developed. For example; when unwanted titanium deposits are built up on the interior surfaces of a reaction chamber, cleaning is conducted using a chlorine gas in combination with temperature control (U.S. Pat. No. 5,983,906). Also, for cleaning an HDP-CVD processing chamber, two-step cleaning is conducted using fluorine-containing gas (U.S. Pat. No. 7,588,036).
However, the above conventional methods using a halide cleaning gas are not effective in cleaning metal oxide or metal nitride, and it is difficult to reduce generation of particles and to reduce a metal contamination level in a film deposited on a substrate after the cleaning.
Any discussion of problems and solutions involved in the related art has been included in this disclosure solely for the purposes of providing a context for the present invention, and should not be taken as an admission that any or all of the discussion were known at the time the invention was made.